The awards, which turn 10 this year, have found a comfortable niche between marking shifting Latino tastes and acknowledging that the acts have a growing number of non-Latinos fans.

Calle 13, the Puerto Rican alt-hip-hop duo, hardly needs more accolades to make its presence known. If not at the pinnacle of their careers, the stepbrothers Rene Perez Joglar, the lead singer known as Residente, and Eduardo Jose Cabra Martinez, a.k.a. Visitante, are entering into Andean altitudes. They've been playing to sell-out crowds at home, in South America and the United States; now Calle 13 leads the pack of this year's Latin Grammy nominees with five.

Among the trophies the duo might haul home from tonight's ceremony at Las Vegas' Mandalay Bay Events Center are those for album of the year ("Los De Atras Vienen Conmigo"), record of the year ("No Hay Nadie Como Tu") and best short form music video, for "La Perla," with Ruben Blades, one of tonight's presenters.

Yet, speaking by phone recently from Venezuela, where he was on tour, Residente said he was grateful that he and other Spanish- and Portuguese-speaking artists have their own separate event from the Grammy Awards. The Latin Grammys, with 49 categories, targets artists across a spectrum of styles, including reggaeton, cumbia, ranchera and religious music.

The Grammys, with only a handful of Latin categories, necessarily lumps many disparate artists into one thick cultural pozole.

"Music is music, but it's good we have a separate award," Residente said. "They [the Grammy Awards] try to incorporate everything, from Mana to Calle 13, and it's crazy."

Celebrating its 10th anniversary, the Latin Grammy Awards has found a comfortable niche between registering shifting Latino musical tastes and sensibilities while catering to an awareness that more non-Latinos, both in the United States and elsewhere, are listening to Spanish- and Portuguese-language music.

The show's presenter, the Latin Academy of Recording Arts & Sciences, no longer feels compelled to argue for its right to a spot in America's saturated entertainment-awards cosmos.

And the awards themselves, now broadcast on the Spanish-language Univision Network, have become a lavish, commercially lucrative affair that reflects the growing importance of U.S. Latinos, who as of 2007 made up 15.5% of the nation's population.

The academy remains a relatively lean operation, however, said its president, Gabriel Abaroa. Each year, he said, its core staff of 10 people relies heavily on a group of about 350 volunteers to listen to and classify all the recordings. The more money the organization saves on overhead costs, said Abaroa, the more it can focus on promoting new talent.

"All the staff that works for the Latin Recording Academy came from Third World countries, where crisis is an everyday word," Abaroa said. "You learn to be very conservative."

In some ways, the Latin music industry has had to rethink its future in the decade since the Latin Grammys and the academy were launched. Back then, the conventional wisdom was that "the crossover moment had arrived," as Ricky Martin and other artists scored a few monster English-language pop hits, Abaroa said.

But that crossover phenomenon never fully arrived, and since then the academy has "become more rootsy," Abaroa maintained. This was possible in part, he believes, because "the American public is accepting much more that someone can sing in Spanish."

Despite the accelerating mainstreaming of Latino culture -- or, if you like, the Latinization of U.S. popular culture -- the Latin Academy seeks to maintain the legitimacy of Latin, non-English music as a distinct cultural entity. That goal is reflected in its stiff rules governing the proportion of Spanish- or Portuguese-language content that recordings must have in order to be nominated.

For any song category, at least 75% of the lyrics must be in Spanish or Portuguese. Album recordings in all categories must have at least 51% Spanish or Portuguese lyrical content.

Tomas Cookman, president and owner of North Hollywood-based Cookman International and Nacional Records, said that although artists and listeners do care about the Latin Grammys, winning seldom does much for a record's sales.

"You don't see those spikes that you do in the general market," said Cookman, whose company's nominated artists this year include Chocquibtown, Hello Seahorse! and Los Amigos Invisibles. "If Norah Jones comes out and wins five Grammys, the next week you'll see sales spike."

One reason for the absence of such an effect, Cookman said, is that over the years the number of Latino music awards shows has proliferated, both in the U.S. and in Latin American countries, competing for television audiences' attentions. Also, he suggested, the sheer number of musical styles can seem daunting.

Cookman thinks that the Latin Grammys might be most useful in bestowing a seal of approval to a Latino artist within the non-Latino market. As an example of how the Latin Grammys isn't always in step with the music world it represents, he pointed to Aventura, a Dominican American Bachata quartet from the Bronx.